1. Field of the Invention
The present invention relates to a thermal ink-jet printer. More particularly, the present invention relates to a structure of ink slots on an ink-jet printhead chip.
2. Description of the Related Art
In thermal ink-jet printer technology, a single ink reservoir on a printhead chip is used to provide inks for all firing chambers formed on the chip. The ink reservoir is connected to the firing chambers by ink slots on the chip. In the practice, the firing chambers are not aligned.
FIG. 1 is a schematic diagram showing a conventional thermal ink-jet printhead chip structure.
Referring to FIG. 1, a plurality of firing chambers 14 is formed on an ink-jet printhead chip 10. Each of the firing chambers 14 has a heater 14a and is connected to a common ink reservoir 12 on the printhead chip 10. In the practice, the firing chambers 14 are not aligned. As shown by the arrangement illustrated in FIG. 1, a distance between each firing chamber 14 and the ink reservoir 12 is not the same. For example, distances 16 and 18 are L1 and L2, respectively.
FIG. 2 is a schematic diagram showing a part of the thermal ink-jet printhead chip structure illustrated in FIG. 1.
Referring to FIG. 2, an ink flow 22 moves toward a firing chamber 26 when the firing chamber 26 is filling with ink from the ink reservoir 12 to prepare for a printing process. Operations of adjacent firing chambers 24 and 28 are disturbed because the pathway of the ink, which fills the firing chambers 24 and 28, is disturbed by the ink flow 22. Response time of the firing chambers 24 and 28 both become longer. Furthermore, a cross talk effect easily occurs between adjacent firing chambers when they operate at the same time or in sequence.
In the foregoing, the distance between each firing chamber and the ink reservoir is not equal, thus a dynamic response of each ink flow is different. Additionally, frequency response is also different for each firing chamber.
In conventional practice, the firing chambers share a single ink reservoir. During the printing process, disturbances occur between the firing chambers, thus the response time of the firing chambers become longer.